Subtle rotations in ancient light: Decoding the universe's symmetry

A team of researchers studying the uncertainties associated with a phenomenon known as cosmic birefringence has developed a method to reduce uncertainties in its observational measurements, according to a new study published in Physical Review Letters on January 27. The study is the first to quantitatively address the uncertainty surrounding the birefringence angle, which is a crucial observational quantity that could provide clues to unknown physical theories breaking the universe's left-right symmetry, and to understanding dark matter and dark energy.